"Boo! Where's the money?" That's what angry protesters could be heard yelling at Amber Heard on a video of the actress exiting the courthouse last month, where she'd spent four days describing the abuse she says that she suffered at the hands of her ex-husband Johnny Depp. "Gold-digger!" one woman, presumably a fan of Mr Depp's, bellowed.

Whatever you think of the verdict in Mr Depp's defamation case against Ms Heard and her countersuit - the jury awarded him more than US$10 million (S$14 million) in damages and her US$2 million - that moment last month leaves one of the big questions of this six-week public spectacle unanswered: What drives a grown person to travel to a courthouse in Virginia to hurl insults at someone she has never met, about behaviour she didn't witness and money she is not owed?